Carboxylic acid-assisted sterically demanding reductive cross-coupling between cycloalkenyl and alkyl bromides

A nickel-catalysed reductive cross-coupling reaction between 2-bromo cycloalkenyl carboxylic acids and alkyl bromides has been developed, affording all-carbon tetrasubstituted cycloalkenes in moderate to excellent yields up to 92%. Mechanistic studies indicated that the carboxylic acid group plays an important assisting role in this sterically demanding coupling reaction.